Hi Luc,
The shuttle is in a slightly lower orbit than the ISS (by about 40 km now), which gives it a velocity advantage to catch up to the station. At some point, the shuttle will boost to an orbit almost identical to the ISS, but still below it. When it does, it will slow the gain of the shuttle on the station so that it approaches at a nice-and-easy pace. This will extend the time it will take for the shuttle to dock with the station. The keps you have define the catchup orbit that the shuttle is currently in, and don't consider the upcoming burn that will slow it down.
I found a website that had some good visuals of these maneuvers if you're interested:
http://resources.yesican-science.ca/iss07/docking.html
73,
Matt Bennett KF6RTB
--- Luc Leblanc [email protected] wrote:
On 9 Aug 2007 at 9:47, Arthur Rowe wrote:on sarex-bb
ISS (ZARYA) 1 25544U 98067A 07220.88563398 .00008468
00000-0 56993-4 0 7430
2 25544 51.6320 191.7165 0008104 217.9929
243.8684 15.76137509499091
STS 118 1 32008U 07035A 07220.96978502 -.00000458
11337-4 44973-5 0 29
2 32008 51.6230 191.3661 0066241 180.9148
357.4615 16.00252620 04
When tracking in simulation both with Orbitron they seems to be in contact around 1051AM August 9 UTC? but rendez vous contact is planned at 1753 on August 10?
(New set of keps for sts-118) from Orbitron
STS 118 1 32008U 07035A 07221.34395840 .00112440 00000-0 45295-3 0 54 2 32008 51.6280 189.4027 0020824 112.0883 48.2798 15.85219015 68
With this new set of keps contact simulation occurs at 0200 AM on the 10
Did anyone have an explanation for theses discrepancies? Even with day 221 set of keps the contact time is now at 0111 August 10 "-"
Luc Leblanc VE2DWE Skype VE2DWE www.qsl.net/ve2dwe WAC BASIC CW PHONE SATELLITE
"-" "It is not the class of license the amateur holds, but the class of the amateur that holds the license."
Luc Leblanc VE2DWE Skype VE2DWE www.qsl.net/ve2dwe WAC BASIC CW PHONE SATELLITE
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